It is known to carry out interrupted polymerization of compounds which contain polymerizable double bonds by heating said compound with a substituted ethane polymerization catalyst, cooling to interrupt the reaction and, when desired, reheating to continue the polymerization reaction. See U.S. Pat. No. 3,378,533. It is also known from U.S. Pat. No. 3,313,863 to produce molded articles by heating storable masses of unsaturated polyesters with conventional copolymerizable monomeric compounds and a substituted ethane catalyst.
It is further known from British Pat. No. 1,041,040 to prepolymerize unsaturated polyester molding masses to a gel stage by moderate heating in the presence of a substituted ethane polymerization catalyst and in the presence of gellers or activators such as mixtures of amine salts and mercaptans. However, the addition of these monomercaptans with amine salt activators render the masses unstable at ambient or moderate temperatures, thereby greatly reducing shelf life. It is also known from U.S. Pat. No. 4,020,233 to form cured polythioethers by admixing a composition comprising an ethylenically unsaturated compound containing at least two unsaturated carbon-to-carbon bonds per molecule, a polythiol containing at least two thiol groups per molecule, a photoinitiator and a catalytic amount of a pinacol and, thereafter, subjecting the admixture to UV radiation and heat.
One object of the instant invention is to produce a composition which can be dual UV and heat cured. Another object of this invention is to produce cured products by exposing a composition by UV radiation followed by the application of heat. Another object of this invention is to produce cured products by simultaneously UV radiating and heating a curable composition.